A known circuit module includes a circuit substrate on which a plurality of mount components are mounted and is mounted to a variety of electronic devices. In general, such a circuit module has a configuration that an electromagnetic shield is formed on a sealing body covering the mount components to prevent an interruption induced by electromagnetic waves (hereinafter referred to as electromagnetic interruption) inside and outside of the module.
In addition, when a plurality of mount components are mounted on the circuit substrate, there is developed a circuit module where the shields are provided to separate the mount components in order to prevent the electromagnetic interruption between the mount components. As the mount components are covered with the sealing bodies as described above, the sealing bodies are partly removed to form trenches (grooves) and the trenches are filled with a conductive material to provide the shields between the mount components.
For example, Japanese Patent Application Laid-open No. 2004-95607 discloses a module component where split grooves are formed on a sealing body covering mount components, and a metal film is formed within the split grooves. The metal film within the split grooves is connected to a ground pattern formed on a circuit substrate and functions as a shield.